MAX1946:Single USB Switch with Autoreset and Fault Blanking in Tiny TDFN

Smallest Single USB Switch with Autoreset and Fault Blanking in Tiny TDFN Package

The MAX1946 single current-limited switch with auto-reset supplies a guaranteed 500mA load in accordance with USB specifications. The MAX1946 operates from a 2.7V to 5.5V input supply and consumes only 40µA of quiescent current when operating and only 3µA in shutdown. Selectable active-high/active-low control logic and shutdown control provide additional flexibility. An autoreset feature latches the switch off in the event of a short circuit, saving system power. The switch reactivates upon removal of the shorted condition. The MAX1946 provides several safety features to protect the USB port. Built-in thermal-overload protection turns off the switch when the die temperature exceeds +160°C. Accurate internal current-limiting circuitry protects the input supply against both overload and short-circuit conditions. An open-drain fault signal, (active-low FAULT), notifies the microprocessor (µP) when a thermal overload, current-limit, undervoltage lockout (UVLO), or short-circuit fault occurs. A 20ms fault-blanking feature enables the circuit to ignore momentary faults, such as those caused when hot-swapping a capacitive load, preventing false alarms to the host system. The fault-blanking feature prevents fault signals from being issued when the device powers up the load. The MAX1946 is available in a space-saving 8-pin (3mm x 3mm) TDFN package and operates over the extended (-40°C to +85°C) temperature range.

Key Features
  • Single USB Switch in 3mm x 3mm Package
  • Autoreset Feature Saves System Power
  • Guaranteed 500mA Load Current
  • Built-In 20ms Fault-Blanking Circuitry
  • Active-High or Active-Low Control Logic
  • Fully Compliant to USB Specifications
  • 2.7V to 5.5V Input Voltage Range
  • Fault-Indicator Output
  • Thermal-Overload Protection
MAX1946: Typical Operating Circuit
MAX1946: Typical Operating Circuit
Applications/Uses
  • Digital Cameras
  • Docking Stations
  • Notebook and Desktop Computers
  • PDAs and Palmtop Computers
  • USB Ports and USB Hubs
DataSheet
titleDownload file
MAX1946 Data SheetMAX1946.pdf
Parametrics
Part NumberUSBPower SwitchesCurrent Limit
(mA)
Current Limit
(mA)
Fault IndicatorCurrent Limit Accuracy
(%)
Current Limit Set ByRON
(Ω)
VSUPPLY
(V)
VSUPPLY
(V)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
minmaxtypminmaxSee Notes
MAX1946Yes1740740Yes24Preset0.0752.75.5-40 to +85TDFN-EP/8$0.58 @1k
Quality and Environmental Data
Related Products
  • MAX893L:1.2A, Current-Limited, High-Side P-Channel Switch with Thermal Shutdown
  • MAX892L:Current-Limited, High-Side P-Channel Switches with Thermal Shutdown
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1946ETA+ActiveTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CLead Free
MAX1946ETA+TActiveTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CLead Free
MAX1946ETA-TNo Longer AvailableMAX1946ETA+TTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CNo
MAX1946.pdf MAX1946
MAX1946.pdf MAX1946
MAX1946.pdf MAX1946
MAX1946.pdf MAX1946
MAX1946.pdf MAX1946